Why You Need a Lawful Development Certificate (Even If You’re Sure It’s PD)

A Lawful Development Certificate is a formal document issued by your local council under Section 192 (proposed works) or Section 191 (existing works) of the Town and Country Planning Act 1990. It confirms that your development is lawful — either because it falls within permitted development rights, or because it has become lawful through the passage of time.

An LDC is not planning permission. It does not grant you the right to do something — it confirms that you already have that right. Once issued, it is a permanent legal record that cannot be revoked (as long as the information in your application was accurate).

1. Selling your home

This is the reason most homeowners wish they had got an LDC sooner — often when they are already under pressure to complete a sale.

When you sell, the buyer’s solicitor will check whether any building work has been carried out and whether it was properly authorised. If there is no planning permission and no LDC, the solicitor will ask questions. The answers you give may not satisfy them.

Without an LDC, you may face:

• Delays — while the solicitor investigates or asks for further evidence
• Indemnity insurance requirements — a one-off policy (£50–£300) that covers the buyer but signals uncertainty about your property
• Price reductions — buyers may negotiate down to account for the perceived risk
• Collapsed sales — in the worst case, a buyer walks away because the uncertainty is too high

An LDC removes all of this. It is a single document that answers the solicitor’s question definitively.

2. Remortgaging

If you remortgage after building work, your lender’s surveyor will note any extensions or alterations. If there is no evidence of authorisation, the lender may:

• Reduce the property valuation
• Require you to obtain an LDC or indemnity insurance before proceeding
• Refuse to lend until the issue is resolved

This can delay a remortgage by weeks. An LDC obtained before or shortly after building avoids the problem entirely.

3. Insurance

Your buildings insurance should cover all structures on your property — but most policies require that building work has been carried out lawfully and with proper approvals. If your insurer discovers that an extension was built without authorisation, they could:

• Refuse to cover the extension
• Refuse a claim relating to the extension (for example, a structural failure or flood damage)
• Increase your premiums

An LDC demonstrates that the work was lawful. Keep it with your insurance documents.

4. Certainty before you spend money

Building an extension costs thousands of pounds — typically £20,000–£60,000 for a single-storey rear extension. Committing that money without formal confirmation that your project is lawful is a risk.

What if you have misread the GPDO rules? What if a previous owner’s extension uses up more of your PD allowance than you realised? What if your property is affected by an Article 4 direction you did not know about?

An LDC costs £274. Your council checks the facts, assesses the GPDO conditions, and confirms in writing that your project is permitted development. If there is a problem, you find out before you start building — not after you have spent £40,000.

5. Peace of mind

Planning rules are complicated. The GPDO has traps that catch experienced architects, let alone homeowners checking the rules for the first time. The “original house” definition, the 50% curtilage rule, the principal elevation restriction, designated land limitations, Article 4 directions — any one of these could mean your project is not PD.

An LDC means you do not have to get it right yourself. The council’s planning officer assesses your project against the GPDO and either confirms it is lawful or tells you it is not. Either way, you know where you stand.

Compare that to the cost of not having one:

The LDC is the cheapest insurance you will ever buy for your building project.

Applying for an LDC is straightforward:

1. Use our free PD checker to get an initial assessment of whether your project is permitted development
2. Get our Permitted Development Certificate Report (£39) — this gives you a full PD eligibility assessment, property constraints check, and application checklist tailored to your project and address
3. Prepare your drawings — you need a site plan, existing floor plans, and proposed floor plans and elevations. An architect or architectural technologist can prepare these for £300–£800.
4. Complete the application form — use form LDCP (for proposed works) or LDCE (for existing works), available from the Planning Portal
5. Write a supporting statement explaining how your project meets the relevant GPDO conditions
6. Submit and pay £274 — via the Planning Portal or directly to your council
7. Wait for the decision — your council should decide within 8 weeks. There is no neighbour consultation for LDC applications.

If approved, you receive a certificate that is a permanent legal record. If refused, you can appeal to the Planning Inspectorate or modify your project and reapply.

An LDC is strongly recommended for most projects, but there are situations where it may not be necessary:

• Very minor works — like replacing a fence with one the same height, or installing a new front door. These are clearly PD and unlikely to be questioned.
• You are not planning to sell — if you intend to stay in the property long-term, the selling risk is less immediate (though it will catch up with you eventually).
• The work is clearly within limits and well-documented — if you have detailed drawings and a clear paper trail, some solicitors may accept this. But many will not.

For anything involving an extension, loft conversion, outbuilding, or roof alteration, an LDC is worth the money.

A refusal is not a disaster — it is useful information. It means the council does not consider your project to be permitted development, and it tells you why.

Your options after a refusal:

1. Review the reasons — the refusal notice will explain which GPDO condition or limitation your project fails. Sometimes this reveals a factual error or misunderstanding that can be corrected.
2. Modify your project — if the refusal identifies a genuine issue (for example, your extension is 100mm too deep), you may be able to redesign to fit within the PD limits.
3. Appeal — you can appeal to the Planning Inspectorate. LDC appeals are decided on the law and the facts, not on planning merit. If the council has misinterpreted the GPDO, an appeal can overturn the decision.
4. Apply for planning permission — if the project genuinely is not PD, you can apply for planning permission instead. This costs £548 and takes around 8 weeks.

Finding out your project is not PD before you build is always better than finding out after.